Sonolor Sensation

Sonolor Sensation

This Sonolor radio was repaired for a customer. Sonolor was a French radio manufacturer. There is no identification on the unit other than the Sonolor insignia on the speaker grille, but the model is believed to be the "Sensation", similar to the Sonolor Rafale. This particular unit made its way from Belgium to Canada with the immigrant owner.

Cabinet designs such as that seen here are unusual compared to North American designs of the period. In North America, radio cabinets went mostly from all-wood of the 1930's to all-plastic for tabletops by the 1950s. A line of European design incorporated a variety of materials: the cabinet of the Sensation includes wood, painted metal, polished metal, mirrored glass dial, and plastic trim.

While working on the cabinet, portions of an unidentifed English-language newspaper were found stuffed inside the compartments on the sides. Dates from 1951 were found in the paper and the writings and references indicate it was an American paper. Topics of discussion include "Mr. Stalin's Atom and Ours", and a proposed St. Lawrence Seaway hydro-electric project. An editorial cartoon takes a poke at Peron and his wife Eva in the midst of an Army coup.

Typical of European radios, the tuning dial is labeled by wavelength rather than frequency and includes a long list of stations identified by city or country. The tuning bands are as follows:

Label	French	Translation	English	Wavelength	Frequency
OC	Ondes Courtes	Waves Short	Shortwave	17 - 50 m	17.6 - 6 MHz
BE	Bande Etalee	Band Spread out	49m Band	46.1 - 51.2 m	6.5 - 5.85 MHz
PO	Petites Ondes	Small Waves	AM Broadcast	200 - 550 m	1500 - 545 KHz
GO	Grandes Ondes	Large Waves	Longwave	1000 - 1900 m	300 - 158 KHz
PU	phono pick-up

Technical

Even though a French radio, a standard North American tube line-up of 6X4, 6AQ5, 6AV6, 6BA6, 6BE6 is used, with the exception of an EM34 dual-sensitivity magic-eye tube.

The speaker is an electro-dynamic type with the field coil in the B+ filter line. Cathode biasing is not used however. Two resistors (200 and 30 ohms) in the B- line develop C- bias for the 6AV6 and 6AQ5 audio stages.

Repair summary (2012 Aug):

6X4 rectifier replaced (fried cathode).
Numerous capacitors replaced.
Power supply and audio area previously worked on, obscuring original design intent. Sorted out as much as possible from what could be discerned and rewired.
Tube-socket pins suffering from metal fatigue, leading to broken lugs and poor contact to tube pins. Broken lugs resoldered, contact improved somewhat by bending, but 6AV6 socket in particular not the greatest.
Weak reception overall. Bad mica capacitor in secondary of 2nd IF transformer replaced with 220pF.
AM band realigned.
Replacement knob moulded (Craig).
Cabinet cleaned and portions reglued.

External links

Sonolor Sensation
Radio Refurb

bhilpert
2012 Aug